maggie, if cimetidine works for you, by all means continue to take it. Cimetidine and ranitidine (the "R" drug I think boz was talking about) are H2 blockers - they block the release of histamine in the GI tract. Since histamine stimulates acid production, the end result is less acid. This is different from the PPIs (nexium, prilosec), which irreversibly block the proton channel itself. The nice thing about ranitidine over cimetidine is that it has far fewer drug interactions. This is only important if you are on other types of medications, like Coumadin (warfarin), Dilantin (phenytoin), B-blockers (like metoprolol), or benzodiazepines (like diazepam). Both ranitidine and cimetidine have the same action, so if you are on any of these meds you should talk with your doctor about H2 blockers (ESPECIALLY cimetidine).
Regarding your preference for natural remedies, it is perfectly understandable and I appreciate your concern. Just remember, many FDA regulated drugs started out as natural remedies (including aspirin), so just because something is a medication does not mean right off the bat that it is toxic, unhealthy or unnatural. Similarly, just because something is natural does not mean it is not without it's risks and side effects (St John's Wart, Valerian, and Ginkgo Biloba all have documented side effects and drug interactions). Don't get me wrong, each aspect of medicine has it's own rightful place in modern healthcare, and the two can even interact symbiotically. With all of the research going on with alternative medicine, it wouldn't surprise me if some of these drugs (especially SJW) went from being natural and alternative to FDA regulated OTCs within the next decade or so. I guess what I'm saying is, if something (traditional or alternative) is working out for you without any side effects, don't stop using it just because it falls into one class or another. If it makes you feel better, keep taking it!